The diverse cold molecular gas contents, morphologies and kinematics of type-2 quasars as seen by ALMA

We present CO(2-1) and adjacent continuum observations of 7 nearby radio-quiet type-2 quasars (QSO2s) obtained with ALMA at ~0.2" resolution (370 pc at z~0.1). The CO morphologies are diverse, including discs and interacting systems. Two of the QSO2s are red early-type galaxies with no CO(2-1) detected. In the interacting galaxies, the central kpc contains 18-25% of the total cold molecular gas, whereas in the spirals it is only 5-12%. J1010+0612 and J1430+1339 show double-peaked CO morphologies which do not have optical counterparts. Based on our analysis of the ionized and molecular kinematics and mm continuum emission, these CO morphologies could be produced by AGN feedback in the form of outflows and/or jets/shocks. The CO kinematics of the QSO2s are dominated by rotation but also reveal non-circular motions. According to our analysis of the kinematics, these non-circular motions correspond to molecular outflows mostly coplanar with the CO discs in four of the QSO2s, and either to a coplanar inflow or vertical outflow in the case of J1010+0612. These molecular outflows represent 0.2-0.7% of the QSO2s total molecular gas mass, have maximum velocities of 200-350 km/s, radii of 0.4-1.3 kpc and outflow rates of 8-16 Msun/yr. These properties are intermediate between those of the mild molecular outflows measured for Seyferts, and the fast and energetic outflows of ULIRGs. This suggests that it is not only AGN luminosity what drives massive molecular outflows. Other factors such as jet power, coupling between wind/jet/ionized outflows and CO discs, and amount/geometry of dense gas in the nuclear regions might be also relevant. Although we do not find evidence for a significant impact of the QSO2s molecular outflows/AGN feedback on the total molecular gas reservoirs and SFRs, they would be modifying the distribution of cold molecular gas in the central kpc of the galaxies.